JP2019500167A - Applicator member of a cosmetic applicator obtained at least in part by molding at least one thermoplastic elastomer material - Google Patents

Abstract

  The present invention relates to an applicator member (8) of a cosmetic applicator, in particular for applying cosmetics to keratin fibers, in particular for applying mascara to the eyelashes. The applicator member is at least partially obtained by molding at least one thermoplastic elastomer material, the material being TPS having a tensile strength of 10 MPa or more, preferably 15 MPa or more.

Description

  The present invention relates to an applicator member for a cosmetic applicator, wherein the applicator member is obtained, at least in part, by molding at least one thermoplastic elastomer material.

  The expression “cosmetic products” is understood to mean any product defined in the European Parliament and Council Regulation (EC) No 1223/2009 of 30 November 2009 on cosmetics.

  The present invention particularly relates to an applicator member for applying cosmetics to keratin fibers, in particular for applying mascara to eyelashes.

  As examples of other shaped applicator members, mention may also be made of applicators for lip products (eg gloss) which may optionally have a flocked application surface.

  In general, such applicator members include a core, which is optionally a set of applicator elements projecting from the core, preferably in a direction substantially perpendicular to the core (especially in a radial direction). Support.

  Applicator members are known for their cores and / or application elements to be obtained by molding one or more thermoplastic elastomer (TPE) materials.

  “Thermoplastic elastomer material” is generally understood to mean a polymer or polymer blend having properties resembling those of vulcanized rubber at the reaction temperature. These properties disappear at the processing temperature and allow later processing, but reappear when the material returns to the reaction temperature (see standard ISO 18064: 2014).

  For general information on thermoplastic elastomer materials, see in particular the guidance of Non-Patent Document 1 published July 10, 2000 by Michel Biron.

  US Pat. No. 6,057,831 describes a mascara brush in which the mascara brush core and applicator element are obtained in a single operation of injection / molding of a plastic material, preferably a polytetrafluoroethylene (PTFE) based elastomer or polymer. ing.

  U.S. Patent No. 6,057,059 describes a brush in which the brush application element and / or core is also made by molding a thermoplastic material. The thermoplastic material used is, for example, SEBS (styrene-ethylene / butylene-styrene), silicone, butyl rubber, EPDM (ethylene propylene diene monomer), nitrile rubber, thermoplastic elastomer (TPE), polyester elastomer, polyamide elastomer, It may be not only a polyethylene elastomer or a vinyl elastomer, but also a polyolefin such as polyethylene (PE) or polypropylene (PP), PVC, PS, PET, POM, PA or PMMA.

  In particular, it is possible to use materials known commercially under the trade names Hytrel (R), Cariflex (R), Alixine (R), Santoprene (R) or Pebax (R), You are not limited to this list.

  In addition, Patent Document 3, Patent Document 4, and Patent Document 5 describing an applicator member obtained by molding a thermoplastic material may be mentioned at least partially.

  U.S. Patent No. 6,099,086 also describes some materials that may be used in the manufacture of a molded applicator. This document includes, in particular, silicone elastomers, thermoplastic elastomers (TPE), eg SEBS, vinyl elastomers (EVA), thermoplastic polyester elastomers (eg, Hytrel® sold by Dupont de Nemours), thermoplastics. References are made to polyurethane elastomers (eg, Pellethane® sold by Dow Plastic), nitrile rubber, EPDM, and the like.

  According to Patent Document 6, the hardness of a material to be selected is preferably 35 MPa (for example, Shore D35 Hytrel (registered trademark) by Dupont de Nemours) to 1180 MPa (for example, Shore D82 Hytrel (registered trademark)). Indicates. Preferentially, the hardness of the selected material is between 95 MPa (Shore D45 Hytrel®) to 570 MPa (Shore D72 Hytrel®). Even more preferentially, the hardness of the material selected is 200 MPa (Hytrel (R) of Shore D55) to 280 MPa (Hytrel (R) of Shore D63).

  In addition, Patent Document 7 can also be mentioned.

  As is evident from many documents, Hytrel (R) is generally a suitable material for the manufacture of molded applicators. Therefore, most molded cosmetic applicators are made from Hytrel®.

  In cosmetic applications, in fact, Hytrel® has many advantages in terms of cosmetic effects.

  In particular, Hytrel (registered trademark) imparts specific responsiveness and repulsive effect to the applicator member and / or the applicator element when the applicator member is used for makeup. Such an effect can be partly objective, in particular by compression at a given compression ratio (eg 30% compression in terms of thickness), eg by testing the applied force.

  Therefore, this material has become a standard in this field.

  In particular, many mascara brushes are made from Shore D51 Hytrel®. Also known are mascara brushes made with Shore D55 and Shore D63 Hytrel®, and also different grades of Hytrel® (eg 50% by weight Shore D47 Hytrel ( (Registered trademark) and 50% by weight of Shore D55 Hytrel (registered trademark).

  From a chemical point of view, Hytrel® is an ether-ester copolymer (COPE) belonging to the thermoplastic elastomer material (TPE) system.

  More specifically, Hytrel® is a block copolymer comprising a hard (crystalline or semi-crystalline) segment of polybutylene terephthalate and a soft (amorphous) segment of polyester based on a long chain glycol. is there.

  The properties of Hytrel®, including the hardness often used in grade names, vary greatly depending on, among other things, the ratio between the hard and soft segments and the chemical composition of these segments.

  This is also shown in a booklet (Non-Patent Document 2) edited by Dupont, a manufacturer of Hytrel (registered trademark).

  Despite its undeniable advantages in the manufacture of cosmetic applicators, there are certain drawbacks to Hytrel®.

  First, Hytrel® and COPE are generally relatively expensive.

  Furthermore, the commonly used Hytrel® material does not fall under food grade (FG) in accordance with EC regulation 1935/2004.

  Secondly, Hytrel (R) and COPE are relatively highly absorbent. For this reason, COPE can absorb water of 4 wt% or less, or even 7 wt% or less.

  Hytrel (R) must be dried prior to extrusion and must be stored in a dry place (see Non-Patent Document 2), so this absorptive property has a significant impact on the manufacturing process. .

  This superabsorbent nature can also have a significant impact on the cosmetic formulation associated with the applicator because of the risk of causing selective absorption of the cosmetic formulation compound.

  In particular, many cosmetic products contain water and at the same time contain soluble and insoluble ingredients and / or additives in this aqueous phase. Thus, excessively high absorption of the cosmetic aqueous phase can lead to cosmetic formulation imbalance and initial formulation denaturation. This entails formulation constraints that are desirable to avoid in advance. This also has an impact in terms of cost since an excessive amount of specific phase or specific compound may need to be added.

  Further, the lower the hardness of Hytrel (registered trademark), the higher the water absorption.

  For this reason, cosmetic applicator manufacturers have studied alternatives to this material and have used other materials in the manufacture of cosmetic applicators.

  Thus, generally known from the above-mentioned materials, those without special features are mascara brush-type commercial applicators, which are the following materials: polypropylene block copolymer, polypropylene blend, COPE, Adflex. (Registered trademark) made of polyolefin, PEBA (especially sold under the standard Pebax).

  However, performance in terms of cosmetic effect is rarely satisfactory and its use is rather brought about by other performance compromises.

  In particular, the Applicant has already marketed SEBS molded mascara brushes and cosmetic applicators.

  From a chemical point of view, SEBS is a block copolymer belonging to the thermoplastic styrene elastomer system (TPS or TPE-S) together with SBS (styrene-butadiene-styrene).

  More specifically, SBS and SEBS include polystyrene hard segments and polybutadiene or poly (ethylene / butylene) soft segments.

  As with Hytrel®, its properties depend in particular on the ratio between the hard and soft segments and the chemical composition of these segments (see Non-Patent Document 1).

  TPS is relatively low cost and is generally more economical than Hytrel®. Furthermore, TPS has limited water or moisture absorption and is significantly less than Hytrel® absorption.

  Thus, SEBS and more generally TPS is the answer to the cost and absorption challenges presented by Hytrel®.

  Furthermore, it is common to add additives to the TPS in order to further enhance its economic advantage. The higher the additive content, the lower the total cost of the material.

For this purpose, it is common to use, for example, CaCO ₃ type inert mineral additives.

  Unlike Hytrel®, whose hardness is evaluated on the Shore D scale, especially intended for hard materials, the hardness of TPS is usually evaluated on the Shore A scale, particularly intended for soft materials (DIN ISO1183-1) ). In the case of SEBS, it is particularly available in food grade with a Shore A hardness of 25-90. There are also some commercial non-food grade SEBS with a particularly high hardness exceeding Shore A 120 or even 140 equivalents (ie approximately Shore D 70-90). Each TPS supplier generally has access to thousands of commercial standards, which may be changed as required.

  In general, in the cosmetic field, the hardness of a material is considered to be an important feature that has a very large influence on the cosmetic properties of a makeup or applicator, in particular the flexibility of the applicator member and the sensory effect of the consumer.

  Patent Document 8 describing a variable-rigidity molding applicator explains that the flexibility of the applicator depends on the type, weight, shape factor, and hardness (durometer) of the material used. Yes.

  U.S. Pat. No. 6,057,059 shows that the hardness of the material affects the application properties of cosmetics or the effectiveness of a specific application method, as is known from U.S. Pat. .

  Patent document 10 itself describes that it is recommended to select a material having a hardness of Shore A6 to 40 in order to produce a cosmetic applicator having high flexibility and high flexibility.

  These documents also explain that at the same material hardness, the flexibility of the application element is substantially derived from the shape.

  Furthermore, with a series of homologous grades, it is believed that the elastic properties decrease with increasing hardness (see Non-Patent Document 1).

  In order to approximate the performance of Hytrel® in a mascara brush, the Applicant has therefore chosen to use a SEBS material with approximately maximum Shore A hardness, ie Shore A90.

  On the Shore D measurement scale, the hardness of Shore A 90 substantially corresponds to the hardness of Shore D 35-40.

  For a lip applicator type applicator, for example, a softer material, in particular a SEBS material near Shore A70, may be selected.

FR 2890838 specification FR 2902984 Specification FR 2910255 Specification FR 2874798 Specification FR 3012303 Specification US Patent Application Publication No. 2015/0020332 International Publication No. 2010/135052 Pamphlet International Publication No. 2012/166777 Pamphlet US Pat. No. 6,481,445 US Pat. No. 5,123,431 US Patent Application Publication No. 2015/0020332

Techniques de l’ Ingenieur, Traite Plastiques et Composites [Treatise on Plastics and Composites], AM 3 400 2013 L-14689-00 All in One Extrusion Processing Manual

  Despite this selection of TPS based on its hardness, the performance from the viewpoint of the cosmetic effect in the same shape is struggling to reach the performance of the applicator member made of Hytrel (registered trademark). It turns out.

  In particular, the application element of the applicator member currently produced with SEBS (TOFI923 Shore A90) has a Shore hardness lower than the Shore hardness of Hytrel (registered trademark) which is conventionally used, but has insufficient elasticity. It turns out that there is, in fact, a softer feel.

  Despite the economic advantages of TPS, this greatly limits its use and Hytrel® remains a preferred material.

  In particular, it is currently not possible to directly use another thermoplastic elastomer material in place of Hytrel® without changing the shape characteristics of the applicator, in particular the applicator element.

  Therefore, there is a need for an economical material that has a low level of water absorption while having the same cosmetic effect as the Hytrel® performance in the same shape.

  In order to do this, the invention relates in particular to an applicator member of a cosmetic applicator for applying cosmetics to keratin fibers, in particular for applying mascara to the eyelashes. The applicator member is at least partially obtained by molding at least one thermoplastic elastomer material, the material being TPS having a tensile strength of 10 MPa or more, preferably 15 MPa or more.

  The tensile strength (or maximum tensile strength) is determined according to standard DIN 53504 / ISO 37 at a speed of 200 mm / min (moving speed) for a standard S2 specimen.

  While not wishing to be bound by any one theory, Applicants have noted that, at substantially the same hardness, the specified tensile strength is similar to that of the conventionally used Hytrel®. It is considered possible to ensure the elastic and mechanical properties.

  In particular, during makeup, the applicator member, and more particularly the application element, deforms (especially due to bending) both in compression and elongation. Therefore, the applicator member should have a certain hardness and a certain tensile strength and bending resistance at the same time.

  In particular, the applicator member should pass through the wiper and to some extent prevent its application to the eyelashes or the part of the body constituting it.

  Advantageously, the TPS material has a tensile strength of 25 MPa or less. Such a maximum value makes it possible in particular to guarantee certain application flexibility and user comfort.

  Preferentially, the TPS material has a breaking elongation of 500% or more, preferably 600% or more. This ensures good elasticity of the applicator member and / or its application element.

  The elongation at break is measured according to the same method as the tensile strength.

  Also preferentially, the TPS material has a breaking elongation of 800% or less, preferably 700% or less.

  In an advantageous supplement, the TPS material has a tear strength of 30 N / mm or more, or even 60 N / mm or more.

  The tear strength (tear resistance) is measured according to standard ISO 34-1 method B (b) (Graves).

  Preferably, the TPS is SEBS.

  Advantageously, the thermoplastic elastomer material has a hardness of Shore A 60 or higher, preferably Shore A 70 or higher, or even Shore A 85 or higher. Such hardness is particularly suitable for cosmetic applicators.

  Also advantageously, the thermoplastic elastomer material has a hardness of Shore A110 or less (equal to about Shore D70), preferably Shore A100 or less (equal to about Shore D60).

  In particular, for mascara brush type applicators, and more generally for skin brushes, a hardness of Shore A 80-100 or even approximately Shore A 90-95 is selected.

  For a lip or skin applicator type applicator, a slightly softer material having a hardness of Shore A 60-80, preferably about Shore A 70, is selected.

  According to one particular embodiment, the TPS material contains at least 15%, preferably at least 20%, or even at least 35% by weight of polyolefin additives.

  In some cases it may be useful to add up to 45 wt%, or even 50 wt% or 55 wt% of polyolefin additives.

  Preferably, the polyolefin additive comprises polyethylene or is further comprised of polyethylene. In particular, the polyethylene can be high density (HD) polyethylene, low density (LD) polyethylene, linear low density (LLD) polyethylene, or radical low density (RLD) polyethylene. Preferably, the polyethylene is high density polyethylene.

  Advantageously, the TPS material contains at most 70% by weight, preferentially less than 60% by weight of polyolefin additives.

According to an alternative or supplemental embodiment, the TPS material comprises less than 20%, preferably less than 15% or 10% or even less than 1% by weight of mineral additive, , CaCO ₃ , aluminum and aluminum compounds, kaolin, and zinc and zinc compounds (especially antimicrobial properties).

While not wishing to be bound by one theory, the Applicant has determined that the mechanical properties of thermoplastic elastomer materials by modifying polyolefins, in particular polyethylene, organic additives and / or mineral additives, in particular CaCO _3. I think it will be possible to greatly influence the characteristics.

  The surface of polyolefin particles with organic and polymer properties is wetted by the polymer used inside. Thus, an interaction that generally results in enhanced mechanical properties occurs between the polyolefin additive particles and the polymer.

In particular, CaCO ₃ mineral particles (preferably 5-10 microns) are easily and uniformly dispersed in the polymer matrix and do not wet with the polymer. There is no interaction between the mineral additive and the polymer. Therefore, calcium carbonate is generally used as an additive to reduce manufacturing costs, and its use is generally considered advantageous.

  The Applicant believes that such additives can actually adversely affect the properties of the cosmetic applicator member. If necessary, this effect could be at least partially compensated or rebalanced using the nature of the long or short segments of the polyolefin additive or TPS material.

  The present application relates in particular to an applicator member according to the invention, characterized in that the applicator member comprises a core supporting a set of projecting applicator elements, extending mainly in a direction perpendicular to the core, in particular radially. And The core may advantageously have a rotational symmetry, in particular a substantially cylindrical shape, or even a frustoconical shape. More specifically, the applicator member is a cosmetic brush, in particular a mascara brush.

  Preferentially, at least some, preferably all, of the application elements are made from TPS material, preferably integral with the core, preferably from the same material.

  The present invention will be better understood upon consideration of the following detailed description with reference to the accompanying drawings.

1 is a schematic cross-sectional view showing an assembly for packaging and applying cosmetics, including an applicator supporting an applicator member molded from at least one thermoplastic elastomer material according to the present application. FIG. 2 is an enlarged schematic view of a mascara brush that serves as an applicator member of the assembly of FIG. 1. The photograph which shows the makeup | decoration result of the applicator of FIG. 2 produced with various materials.

  FIG. 1 shows an assembly 1 for packaging and applying cosmetics. The assembly 1 has an applicator 2 and an associated container 3 that contains a product P to be applied to the eyelashes and / or eyebrows, for example a mascara or a care product.

  In a state known per se, the container 3 has a threaded neck 4 so that the applicator 2 can be mounted on the neck 4 to close the container 3 in a sealed state when the container 3 is not in use. A closure cap 5 designed in The closing cap 5 also constitutes a gripping member for the applicator 2.

  The applicator 2 has a shaft portion 7 having a longitudinal axis Y. The shaft portion 7 is attached to the closing cap 5 at its upper end and is attached to the applicator member 8 at its lower end. The applicator member 8 has a core 10 that supports an applicator element 18 that extends from the core 10 to the entire periphery of the core. The application element 18 is in the form of a spike, but other application element shapes can of course also be envisaged.

  As shown in FIG. 2, the core 10 has a substantially cylindrical shape.

  The container 3 also has a wiping member 6 inserted into the neck 4. This wiping member 6 (which may be of any suitable type) is designed in this example to wipe off the shaft 7 and the applicator member 8 when the applicator 2 is removed from the container 3. Has a lip. The lip defines a wiping hole 6 a having a diameter that matches the diameter of the shaft 7. The wiping member 6 may be made of an elastomer. The wiping hole 6a has a circular shape, for example.

  As shown in FIG. 2, the applicator member 8 may have an end piece 9 for mounting the applicator member 8 in a corresponding housing in the shaft 7.

  The applicator member 8 may be mounted in this housing in the shaft 7 by any means, in particular by press-fitting, snapping, adhesive bonding, welding, stapling or crimping.

  Referring to FIG. 2, it can be seen that the core 10 has an elongated shape along a longitudinal axis X, which is a straight line in the example described. As shown, the longitudinal axis X may be centered.

  In the illustrated example, each application element 18 extends from the core 10 along an elongated axis that is substantially perpendicular to the surface of the core 10 where the application element 18 is attached to the core 10.

  To use the device 1, the user loosens the closure cap 5 and removes the applicator member 8 from the container 3.

  When the applicator member 8 passes through the wiping member 6, a certain amount of product P remains between the spikes 18, in the grooves of the reinforcing web 13 and between the rows, and the spike 18 has its base when passing through the wiping member 6. The storage part of the product P is formed along the entire length and the entire surface of the core 10 without bending, and the product P can be satisfactorily placed on the eyelashes and / or eyebrows.

  According to the present application, the applicator member 8 is at least partially made of a TPS-based thermoplastic elastomer material, in particular SEBS.

  More specifically, the applicator member 8 is produced by molding, in particular according to the injection molding method well known to those skilled in the art, for example, described in Patent Document 11.

  Preferably, all or some of the application elements 18 are integrally formed with the core 10. Alternatively, the application element can be overmolded over the central portion forming the core 10.

  The thermoplastic elastomer material used has a tensile strength of 10 MPa or more, preferably 15 MPa or more.

  Preferentially, the TPS material has a tensile strength of 25 MPa or less.

  The TPS material may also have an elongation at break of 500% or more, preferably 600% or more. The elongation at break is preferably less than 800%, preferably less than 700%.

  In addition, the TPS material may have a tear strength of 30 N / mm or more, preferably 60 N / mm or more.

  The TPS material selected for the production of the applicator member 8 (mascara brush) advantageously has a hardness of Shore A 70-110, preferably Shore A 85-100, in particular approximately Shore A 90 or 95.

  The mechanical properties of the selected TPS material may be adjusted in various ways, particularly with additives.

  Thus, the TPS material contains at least 15 wt%, preferably at least 20 wt%, or even at least 35 wt%, or else at least 45 wt%, up to more than 55 wt% polyolefin additive, The additive preferably comprises polyethylene or further consists of polyethylene.

  Preferably, the polyolefin additive remains below 70% by weight, or even below 60% by weight.

  As mentioned above, the Applicant believes that inert mineral additives, unlike polyolefin additives, negatively affect the desired mechanical properties.

  Accordingly, it is preferred that the selected TPS material comprises less than 20 wt%, preferably less than 10 wt%, or even less than 1 wt% mineral additive.

In particular, the mineral additive may be selected from CaCO ₃ , aluminum and aluminum compounds, kaolin, and zinc and zinc compounds. In particular, it may be advantageous to select mineral additives having additional properties such as bactericidal properties.

  Such materials are commercially available from many manufacturers, particularly Kraiburg or Mitsubishi Chemical Corporation.

  The following table provides a list of available material criteria that may be particularly suitable for the manufacture of applicator members 8 according to the present application. Table 1 also lists standard materials that are currently in use and are not completely satisfactory for the reasons detailed above. Standard materials are shown in italics.

  The applicator member 8 was molded from several materials and tested for their cosmetic performance.

  The following table (Table 2) shows the results after approximately 20 passes per eye through applicator members containing the same mascara formulation as evaluated by a cosmetic sensory test specialist.

DESCRIPTION OF SYMBOLS 1 Assembly 2 Applicator 3 Container 4 Neck part 5 Closing cap 6 Wiping member 6a Wiping hole 7 Shaft part 8 Applicator member 9 End part 10 Core 13 Reinforcement web 18 Application element, spike

Claims (13)

  In particular, an application member (8) for a cosmetic applicator for applying cosmetics to keratin fibers, in particular for applying mascara to the eyelashes, at least partly forming at least one thermoplastic elastomer material In the application member (8) obtained by the method, the material is TPS having a tensile strength of 10 MPa or more, preferably 15 MPa or more.   The application member (8) according to claim 1, wherein the TPS material has a tensile strength of 25 MPa or less.   Application member (8) according to claim 1 or 2, characterized in that the TPS material has a breaking elongation of 500% or more, preferably more than 600%.   Coated member (8) according to any one of claims 1 to 3, characterized in that the TPS material has a breaking elongation of less than 800%, preferably less than 700%.   The application member (8) according to any one of claims 1 to 4, characterized in that the TPS material has a tear strength of 30 N / mm or more, preferably 60 N / mm or more.   The application member (8) according to any one of claims 1 to 5, wherein the TPS material is SEBS.   The application member (8) according to any one of claims 1 to 6, characterized in that the thermoplastic elastomer material has a hardness of Shore A 60 or higher, preferably Shore A 70 or higher, or even Shore A 85 or higher.   The application member (8) according to any one of claims 1 to 7, wherein the thermoplastic elastomer material has a hardness of Shore A110 or less, preferably Shore A100 or less.   The TPS material contains at least 15% by weight, preferably at least 20% by weight, or even at least 35% by weight of polyolefin additive, said polyolefin additive preferably comprising polyethylene or further comprising polyethylene. The application member (8) according to any one of claims 1 to 8, wherein the application member (8) is provided.   10. Applicator member (8) according to claim 9, characterized in that the TPS material contains at most 70% by weight, preferentially less than 60% by weight of polyolefin additives. The TPS material comprises less than 20% by weight, preferably less than 10% by weight, or even less than 1% by weight of a mineral additive, said mineral additive being CaCO ₃ , aluminum and aluminum compounds, kaolin, and zinc and zinc compounds The application member (8) according to any one of claims 1 to 9, wherein the application member (8) is selected from the following.   12. An applicator member (8) according to any one of the preceding claims, comprising a core (10) supporting a set of projecting applicator elements (18).   13. At least some, preferably all, of the application elements (18) are made from TPS material, preferably integral with the core (10), preferably from the same material. Application member (8).